18 Gal.

This is a discussion on 18 Gal. within the Beginner Planted Aquarium forums, part of the Beginner Freshwater Aquarium category; -->
So i've been wondering around the internet and different forums. i've done a little research and i need your advice. I currently have a ...

So i've been wondering around the internet and different forums. i've done a little research and i need your advice. I currently have a 18 gal. that is 20inches wide X 20inches high X 10inches deep, a DIY type co2 system, a rocky substrate (with little to no nutritional value), with every water change i put in plant nutrients, and a light that is 18w 12000k. I know i currently have 1wpg. I'm trying to get myself to 2wpg in hopes that my plants will become healthier. My plants have been doing fairly fine with my set up, however, they seem like they could be healthier.

This is where you come in . . . can you guys recommend a good/cheap lighting fixture that will provide medium light for my aquarium?

I would be interested in knowing what it is about your plant growth that seems wrong before suggesting something. A description would be nice, including what specific plant species and how they appear. A photo would be wonderful, worth the proverbial thousand words.

Also, which specific "nutrients" are you using, by which I mean the fertilizer brand if a general one or if individual nutrients, which ones and what manufacturer. These things can be very significant.

Once I know something about your setup and any problems, I may be able to make suggestions for improvement.

rotala indica: it seems like this plant is falling apart. many of the leaves are falling off and have holes in them.
ludwigia ovalis: many of the lower leaves have fallen off, however the top ones are looking pretty green.
amazon sword: it seems pretty healthy. although some of the leaves are looking transparent.
hygrophila balsamica: the color makes me think it is doing healthy, and there are some new growths coming from the bottom of the plant, some parts of the bunch are falling apart.

I also have some plant that i don't know what it is . . . but it seems to be doing alright. I also have some purple waffles that i know i'll have to take out eventually because they're not aquatic plants.

Well, aside from the plant in the first photo, you have no problems that I can see; the other plants are doing very well in my view. But I have a couple suggestions.

First on the "not so good looking" plant, I think it is Rotala macrandra which comes from India so could well be named Rotala indica by some stores/growers. This plant requires very bright light. Plants most require blue and red light. We perceive "colour" because of reflected light from an object; therefore, a plant that appears red is reflecting a fair amount of red light, just as green plants reflect green light. Because the plant uses red light in photosynthesis, and is reflecting some of it at the same time, it needs even more light to grow. That is why all red-leaved plants will not have rich red leaves unless grown in quite intense light. So, I would suggest you either forget about this plant, or be prepared to increase the light to provide what it requires. But this leads to other issues with your other plants, as I'll explain, so my suggestion would be to forget this plant.

The loss of lower leaves on the ludwigia is common with many stem plants because the lower leaves receive less light and stem plants are fast growing plants. The faster a plant grows, the more nutrients and light in balance it requires. It will grow up to the surface and then across it to grab as much light as it can. The solution here is to plant the ludwigia behind something, like a piece of wood or rock, or behind low growing plants like pygmy chain swords or crypts; then the lower stems are not so obvious. But, as with all stem plants, it has to be "trimmed" regularly. Removing the entire plant, you cut off the lower portion of the stems and replant the upper portions. This has to be done regularly, maybe every week or every two weeks, depending upon how fast the plant grows. I do this with my pennywort just to keep it within bounds, otherwise it would cover the surface. This is one disadvantage of stem plants, they are high maintenance, compared to rooted plants like swords, crypts, aponogeton, etc that basically stay where you plant them.

Water sprite is Hygrophila difformis. It is a stem plant, so the above-described maintenance will be required. This plant also tolerates less light for a stem plant, although in less light the lower leaves sometimes come off and may be replaced with wider leaves. The brighter the light the narrower or more lace-like are the leaves on the entire plant. I have a tank of this, my 70g SE Asian, if you want to check the photos under my Aquariums. I regularly pull each of these stems up and trim them as I explained above.

Your sword (I suspect it is Echinodorus bleheri) looks good to me, I can't see the "transparency" in the photo, but if it is, that is simply a sign of insufficient nutrients. Iron is required for these plants, but not as much as some people would have you believe, and other nutrients have to be present in porportion or the plant will not grow well. Yellowing and/or transparent leaves can be caused by several nutrient deficiencies. Hard to see in the photo, but there appears to be new growth (leaves) emerging from the centre of the crown, so that is good. As these plants grow, outer leaves are often lost; they start to yellow, at which I usually just cut them off, provided I see the new growth in the centre. A good substrate fertilizer would help this plant, and any sword. I use Nutrafin's Plant-Gro sticks, one next to this plant lasts a year, and will provide amazing growth and size. Seachem's Flourish root tabs also work. And there may be others I haven't tried.

Last on fertilizer, I would recommend Seachem's Flourish Comprehensive Supplement for the Planted Aquarium or Kent Freshwater Plant Supplement. I've used both, and they are very good. FloraPride I have researched and it is not a complete fertilizer. It may be adequate until it's gone, particularly if you get a root stick for the sword, but use the Flourish Comprehensive or Kent afterwards. Root fert is useless for stem plants and plants not rooted in the substrate (floating plants, Anubias, Java Fern, mosses...) since they have roots in the water column and liquid fertilizer gets to them more efficiently.

To sum up a bit on the light issue, there has to be a balance between the available light and the available nutrients (there are 17, including carbon which mainly comes from CO2 produced by the fish and biological processes). Good plant growth occurs when all this is in balance. Over-providing any one thing will not result in better growth but frequently creates other problems with the plants and/or algae. That is why I do not recommend increasing your light for the red plants, because the nutrients will not be in balance. Not all plants will grow in the same conditions; and some plants actually inhibit other plants chemically. The trick is to get the right balance of plants for the conditions in your aquarium, and then they will thrive. Look at my tank photos; I avoid stem plants (except the Pennywort and Hygrophila difformis that tolerate my lower lighting), but the plants I have are a good variety and contrasts and they are all growing well.